The most widely used textile materials today include synthetic resins such as polyesters represented by polyethylene terephthalate and polyamides represented by 6-nylon and 66-nylon.
While these synthetic resins are advantageous in their capability of cheap mass production, they involve some problems related to their disposal. The textile made of such synthetic resins can be hardly decomposed in the natural environment, and high heat of combustion is generated by incineration.
Under these situations, use of biodegradable synthetic resins such as polycaprolactone and polylactic acid for textiles have been proposed. Although these resins are excellent in biodegradability, they are still not suitable for practical applications as compared with non-degradable synthetic resins such as polyethylene terephthalate and nylon that have been widely used.
These problems are poor process throughput during the producing process (spinning, drawing, false twisting and the like), inferior properties such as tensile strength and elongation percentage of the textile products obtained as compared with conventional synthetic fibers.
The inventors of the present invention have made intensive survey on the physical and chemical properties of polylactic acid, and have investigated polylactic acid resins particularly suitable for use in the textile products. We have also found polylactic acid textile products being excellent in productivity and having favorable properties by using polylactic acid having selected properties, and a process for producing the textile products. The object of the present invention is to provide practically acceptable textile products comprising polylactic acid having excellent properties for use in textiles with high productivity.